Blood-Based Testing, Telehealth Help Close Biomarker Access Gaps

Biomarker testing remains a cornerstone of precision oncology, particularly for non–small cell lung cancer, yet obstacles like insufficient tissue samples and lengthy turnaround times continue to complicate timely treatment decisions, according to Shiven B. Patel, MD, MBA, of the Huntsman Cancer Institute.

In an interview with The American Journal of Managed Care^® (AJMC^®) at a recent Institute for Value-Based Medicine® event in Salt Lake City, Utah, Patel, who moderated the “Precision in Practice: Implementing Biomarker Testing in Lung Cancer” panel, discussed strategies for closing these gaps, including the expanding role of blood-based testing, mobile phlebotomy services, and telehealth in extending access to rural patients.

He also explained how he sequences tissue and blood testing to balance the urgency of starting treatment against the risks of switching therapies before results are finalized.

This transcript has been lightly edited for clarity.

AJMC: What challenges most often prevent comprehensive biomarker testing from being completed at diagnosis, and what changes have been most effective in addressing these gaps?

Patel: They say tissue is the issue, right? A lot of times, we just get a scant amount of tissue. I just had an email on the way here where they're saying there wasn't enough tissue to do testing. If we can get higher-yield biopsies and better technology that way, that would be great.

One of the things that helps is blood-based testing. If we can't get tissue, we can do circulating tumor DNA next-generation sequencing on blood, but there are still limitations. One, you can’t always be sure there’s circulating tumor DNA in the blood. Two, we still don't have technology to run RNA sequencing in blood as we do in tissue, and RNA sequencing is incredibly important, especially in lung cancer, to find actionable fusions.

We're getting more and more antibody-drug conjugates and things like testing for PD-1. Those are immunohistochemistry stains, so right now that has to be done on tissue as well. Blood still doesn't fill all the gaps, but it's better than nothing.

AJMC: For those who live far from a cancer center, what strategies or tools have helped ensure that biomarker testing and results can be coordinated closer to home?

Patel: At the end of the day, the nice thing is all these biomarker testing companies are really generous, and they know what needs to be done, and so they actually go get the tissue where it is. So, if the patient got a biopsy at the local hospital, we put that in the requisition form, and they go and get it wherever it is and then take it to their central lab to run the testing. The other thing is, a lot of these services actually do mobile phlebotomy. So, if you want blood-based testing, they'll drive to rural areas, and they'll have their phlebotomist go to their house and draw it for me; they've really improved access.

Then, what I do is a lot of telehealth. I'm licensed in the 8 surrounding states. We have a huge catchment area. If all I need is to check on them or just say, "Hey, this test was positive or negative," why make them drive 5, 10 hours each way? I've got licensed in all these states, so I can do a quick telehealth. I adopted telehealth at the beginning of the pandemic because I had a clinic in Idaho. For a couple of months, I was not allowed to travel because of the pandemic rules. I saw those patients for a month via telehealth. I got very comfortable doing it.

AJMC: When biomarker results are delayed, what strategies have been most useful for reducing turnaround time? At the same time, how do you navigate treatment decisions when results are not back yet?

Patel: One thing I like to do is order the tissue and the blood concurrently, and the blood comes back in a week. If it's positive, I can get going with the appropriate targeted therapy. If it's negative and the patient's clinically stable, I'll wait for tissue to confirm it's completely negative before starting chemoimmunotherapy. If the patient can't wait because they're sick and really need treatment for response to feel better, then I'll start chemotherapy without immunotherapy for a cycle.

By the time they're due for their next cycle, I should really have the test back. That's enough time. I'll add immunotherapy if there’s nothing actionable, and our guidelines say that if we do find something actionable, we should switch immediately. But I do it that way because if you have some immunotherapy in your system when you switch to a targeted therapy, that can lead to extra toxicity. By foregoing immunotherapy with that first cycle of chemotherapy, you avoid that risk until you're absolutely sure you're not going to be switching the patient to targeted therapy.